Amorphous silica products, articles, and particles and methods of producing amorphous silica products, articles, and particles from concrete

ABSTRACT

Concrete may be melted to form a glass product. Methods and batch compositions including concrete may be used to produce amorphous silica materials including, but not limited to, glass, container glass, fiber glass, glass bead, glass spheres, sheet or plate glass, glass aggregate, glass sand, abrasives, proppants, foamed glass, and manufactured glass articles. The initial processing steps include preparing a melt batch comprising concrete and, optionally, other components, melting the melt batch, and cooling the melted melt batch. Further processing steps may be utilized to produce the glass article.

TECHNICAL FIELD

Embodiments of the method of invention comprise producing amorphoussilica glass products, articles, particles, sheets, fibers, or otheramorphous silicate products from natural crystalline silica sand, glasscullet, concrete including new and recycle Portland cement concrete.Concrete comprises aggregates that may include crystalline silica.However, airborne crystalline silica has been determined to be ahazardous substance that has been shown to cause silicosis if inhaled.

Embodiments of a method include heating concrete a temperature in whicha significant portion of the crystalline silica is converted intoamorphous silica. For example, concrete such as recycled Portland cementconcrete may be mixed with other components to provide the desiredproperties to assist in processing and/or product properties such as,but not limited to, melting temperature, melt viscosity, processefficiency, density, toughness, hardness, or other desired properties.

For example, recycled concrete may be heated in the presence of fluxingcomponents, density increasing components, hardness increasingcomponents, decolorants, and other property enhancing components. Thedensity increasing components may be metal oxides, metal silicates,silicides, aluminum oxide, zirconium oxide, clays comprising aluminumoxide, zirconium oxide, or a combination of aluminum oxide, iron oxide,and zirconium oxide. Other density increasing components includetitanium oxide and other transition metal oxides.

Embodiments also include products produced from the concrete or recyclePortland cement concrete. For example, embodiments of the productsinclude crystalline silica free sand, gravel, cullet, blastingabrasives, concrete mixes, grout, manufactured stone, mortar, bricks,concrete blocks, other concrete products, pavers, glass, containerglass, flat glass, and other products that would benefit from theinclusion of concrete or recycled concrete.

BACKGROUND

Approximately ten billion tons of concrete are manufactured each year.Concrete is used for building many structures including roads,sidewalks, bridges, buildings, driveways, walls, and parking areas, forexample. As these structures reach the end of their useful life or areto be removed for new construction, the concrete is typically demolishedand considered a waste material.

This waste concrete may be sent to a land fill or recycled. Concreterecycling is an increasingly common method of utilizing the waste.Though there is not enough demand for recycled concrete and, therefore,concrete is routinely trucked to landfills for disposal.

Concrete aggregate collected from demolition sites may be put through acrushing machine to reduce the size of the aggregate. Crushingfacilities accept only uncontaminated concrete, which must be free oftrash, wood, paper and other such materials. Metals such as rebar areaccepted, since they can be removed with magnets and other sortingdevices and melted down for recycling elsewhere. The remaining aggregatechunks are sorted by size with larger chunks passing through the crusheragain until the desired size is reached. After crushing has taken place,other particulates are filtered out through a variety of methodsincluding hand-picking and water flotation.

However, the concrete aggregate may comprise sand. It has been foundthat respirable airborne particles of crystalline silica sand may enterthe lungs of people in and around any area. Respirable crystallinesilica sand in the lungs may result in the development of silicosis anda host of other illnesses. Silicosis is one of the world's oldest knownoccupational diseases, with reports of employees contracting the diseasedating back to ancient Greece.

Airborne crystalline silica dust may be produced during themanufacturing, recycling and reuse process of the concrete.

There is a need for additional methods of using, reusing and recyclingconcrete and production of safe products from waste concrete.

SUMMARY

Embodiments of the method may be used to produce amorphous silicamaterials including, but not limited to, glass, container glass, fiberglass, glass bead, glass spheres, sheet or plate glass, glass aggregate,glass sand, abrasives, proppants, foamed glass, and manufactured glassarticles. The initial processing steps include preparing a melt batchcomprising concrete and, optionally, other components, melting the meltbatch, and cooling the melted melt batch. Further processing steps maybe utilized to produce the glass article. These finishing processingsteps are known in the art and may be applied as known in the art duringthe cooling step or in addition to the method. Such steps are used toproduce the glass, container glass, fiber glass, glass bead, glassspheres, sheet or plate glass, glass aggregate, glass sand, abrasives,proppants, foamed glass, and manufactured glass articles. Typicalcontent of OPCC of approximately 81% SiO2, 13% CaO, <0.7% Fe2O3, and <5%aluminum oxide makes it an effective feedstock in varying amounts fornearly all types of glass by balancing total oxide contents in thedesired finished glass with supplemental oxides from separate sources ofsilicon dioxide, boron trioxide, aluminum oxide, magnesium oxide, zincoxide, sodium oxide, potassium oxide, iron oxide, titanium oxide, etc.These components may be added to a glass batch alone or in combination.

Embodiments of a method of producing a manufactured glass articlecomprise melting concrete. Concrete is a mixture comprising Portlandcement (Types I though V) or blended cement (Types IL, IS, IP, or IT),aggregate (coarse and fine), water of hydration, and, optionally,admixtures. The admixtures may include mineral (fly ash types F or C,slags), fibers, water reducers, air entraining agents, and rheologymodifiers, for example. Other cements used in concrete include low-ironcements (white cement), and high-alumina cements (for example magnesiumphosphate).

The concrete in embodiments of the method may be new, waste or recycledconcrete. Recycled concrete being any concrete that has been taken outof service. Waste concrete may be excess concrete or concrete that doesnot meet strength or other required properties for the application andwashout concrete from ready mix concrete trucks and mixers, for example.

In one embodiment, a method of producing an amorphous silica materialcomprises preparing a batch comprising concrete and melting the batch ina furnace to produce a melt effluent, molten glass, or molten mass. Allbatches described herein may be thermally processed by melting, fusingor sintering. Sintering or fusing of the components of the batch shouldbe performed sufficiently to convert a significant amount of thecrystalline silica into amorphous silica such as below toxicity levelsfor applications that will result in airborne dust. The method maycomprise additional processing steps to prepare the melt effluent,molten glass, or molten mass (melt effluent) into a product. Therefore,the melt effluent may be subject to further processing such as, but notlimited to, cooling, annealing, quenching to produce particles or anamorphous mass, air cooling, placing in a mold for a “blow and blowmethod” or a “press and blow method” for producing container glass,using a gob in the Westlake process, glass blowing (free, mold ormodern), floating the melt effluent for flat glass, or other processingsteps to produce glass products.

Embodiments of the method comprise making. The method of claim 1,comprising crushing the amorphous silica particles or mass to formparticles. The particles may be used as abrasives media, proppants,frits, or other applications for particles. Additionally, embodiments ofthe method comprise molding the melt effluent, amorphous silicaparticles or mass to form a glass container or other glass article.Further, embodiments of the method may comprise floating the melteffluent to form a sheet of glass, wherein the mass is the sheet ofglass.

The batches may comprise additional components. For example, concretemay be mixed with other components in a batch to provide the desiredproperties to assist in processing and/or product properties such as,but not limited to, melting temperature, melt viscosity, processefficiency, density, toughness, hardness, or other desired properties.

The additional batch components may comprise glass cullet, glass fluxes,at least one metal oxide, at least one metal silicate, at least onemetal, iron oxide, magnetite, calcium containing material, limestone,lime, silica sand, feldspar, metal slags, furnace slags, combustiblematerials, colorants, decolorants, fining agents, oxidizers, andreducers, for example. Calcium containing materials include, but are notlimited to, furnace slag, lignite ash, coal ash, and lime residues fromprocessing, for example.

An embodiment of the method of producing a manufactured glass articlecomprises preparing a batch consisting essentially of concrete. Theembodiment may further comprise melting the batch in a furnace to melteffluent and cooling the melt effluent to form amorphous silicaparticles, mass or product. The batch may further comprise at least oneof colorants, decolorants, fining agents, oxidizers, and reducers.

A further embodiment of the method of producing an amorphous silicamaterial, comprising preparing a batch consisting essentially ofconcrete and glass cullet. Such an embodiment may further compriseadditional steps as described herein and know in the art. A stillfurther embodiment of the method of producing an amorphous silicamaterial comprising preparing a batch consisting essentially ofconcrete, fluxes, and glass cullet.

In another embodiment, a method of producing an amorphous silicamaterial, comprising preparing a batch consisting essentially ofconcrete, sand, limestone, and glass cullet.

Further additional embodiments include a method of producing anamorphous silica material comprising preparing a batch comprisingconcrete, iron oxide, and cullet.

A still further additional embodiment of the method of producing anamorphous silica material comprises preparing a batch consistingessentially of concrete, iron oxide, and cullet.

An embodiment of the method of producing an amorphous silica materialcomprises preparing a batch comprising concrete and metal slag.

Embodiments of the method may comprise preparing a batch comprisingconcrete and metal oxides, such as, but not limited to, iron oxide,alumina, and zirconia, for example. The concentrations of metal oxidesresult in the resultant amorphous silica product with a density andhardness above the density and hardness of typical recycled glass. Theamorphous silica product may be substantially free of deleterious levelsof toxic or heavy metals. As used herein, the term “substantially freeof deleterious levels of toxic or heavy metals” means that theenvironmental and industrial hygiene organizations do not consider theamorphous silica product toxic if used as intended.

The methods may be used to prepare amorphous silica products. Such asthe amorphous silica products described in the US patent applicationentitled “Amorphous Silica Particles and Methods of Producing AmorphousSilica Particles” filed on the same day as the application.

The density of embodiments of certain embodiments of the amorphoussilica products is correlated with increasing concentrations of metaloxides including but not limited to, iron oxides, zirconium oxides,aluminum oxides, and combinations thereof, for example. Embodiments ofthe amorphous silicate products may have a density in the range of 2.5g/cc to 3.5 g/cc. Embodiments with higher concentrations of iron oxideand/or other metal oxides or other density increasing components mayhave a density in the range of 2.8 g/cc to 3.5 g/cc.

Further, the hardness of embodiments of the amorphous silica product iscorrelated with increasing iron oxides, zirconium oxides, aluminumoxides, and combinations thereof. Embodiments of the amorphous silicateproduct have a Knoop hardness in the range of 520 Hk to 750 Hk.Embodiments with higher concentrations of the metal oxides may have aKnoop hardness in the range of 600 Hk to 750 Hk.

Metals may also be added in their pure metal form or as an alloy. Themetals include, but are not limited to, iron, aluminum, titanium,zirconium, manganese, magnesium, alloys and combinations thereof. Themetals may be melted in a furnace in the presence of oxygen (air) to atleast partially form oxides or in a furnace with an inert atmosphere tomelt directly into the amorphous silica.

The fluxes may include any fluxes typically used in glass manufacturingand may include, but are not limited to, sodium oxides, magnesiumoxides, potassium oxides, lithium oxides, boric oxides, and combinationsthereof, for example.

Typical particle sizes for blasting abrasives are in the range of meshsize 20/30, 30/70, and 50/100, for example. These mesh sizes may,typically, include 10% of the particles above or below the stated meshsize range.

The glass batch need only be converted to an amorphous silica, not fullymelted. The cooling and crushing processes may be designed for economy,to deliver the desired properties, and to provide ease with theproduction of sand sized particles in the desired particle size ranges.Embodiments of the process to produce amorphous glass products may besummarized as an efficient method of producing crushed, recycled glassparticles with higher density and improved hardness directly fromcrystalline silica materials for the same cost as recycle glass or fromcullet to enhance the properties for specific applications.

Components that may be added that do not materially affect the basic andnovel characteristics of the claimed invention include, but are notlimited to, do not materially affect the basic and novelcharacteristic(s)” of the claimed invention. The secondary, additivematerials may include colorants, decolorants, fining agents, oxidizers,reducers, or any other additive that does not contribute to the mainoxide content of the glass.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by onehaving ordinary skill in the art to which this invention belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure and will not be interpreted in an idealized or overlyformal sense unless expressly so defined herein.

In describing the invention, it will be understood that a number ofcomponents, parts, techniques and steps are disclosed. Each of these hasindividual benefit and each can also be used in conjunction with one ormore, or in some cases, all of the other disclosed embodiments andtechniques. Accordingly, for the sake of clarity, this description willrefrain from repeating every possible combination of the individualsteps in an unnecessary fashion. Nevertheless, the specification andclaims should be read with the understanding that such combinations areentirely within the scope of the invention and the claims.

DESCRIPTION

Embodiments of the method may be used to produce amorphous silicamaterials including, but not limited to, glass, container glass, fiberglass, glass bead, glass spheres, sheet or plate glass, glass aggregate,glass sand, abrasives, proppants, foamed glass, and manufactured glassarticles. The initial processing steps include preparing a melt batchcomprising concrete and, optionally, other components, melting the meltbatch, and cooling the melted melt batch. Further processing steps maybe utilized to produce the glass article. These finishing processingsteps are known in the art and may be applied as known in the art duringthe cooling step or in addition to the method. Such steps are used toproduce the glass, container glass, fiber glass, glass bead, glassspheres, sheet or plate glass, glass aggregate, glass sand, abrasives,proppants, foamed glass, and manufactured glass articles. Typicalcontent of OPCC of approximately 81% SiO2, 13% CaO, <0.7% Fe2O3, and <5%aluminum oxide makes it an effective feedstock in varying amounts fornearly all types of glass by balancing total oxide contents in thedesired finished glass with supplemental oxides from separate sources ofsilicon dioxide, boron trioxide, aluminum oxide, magnesium oxide, zincoxide, sodium oxide, potassium oxide, iron oxide, titanium oxide, etc.These components may be added to a glass batch alone or in combination.

Embodiments of a method of producing a manufactured glass articlecomprise melting concrete. Concrete is a mixture comprising Portlandcement (Types I though V) or blended cement (Types IL, IS, IP, or IT),aggregate (coarse and fine), water of hydration, and, optionally,admixtures. The admixtures may include mineral (fly ash types F or C,slags), fibers, water reducers, air entraining agents, and rheologymodifiers, for example. Other cements used in concrete include low-ironcements (white cement), and high-alumina cements (for example magnesiumphosphate).

The concrete in embodiments of the method may be new, waste or recycledconcrete. Recycled concrete being any concrete that has been taken outof service. Waste concrete may be excess concrete or concrete that doesnot meet strength or other required properties for the application andwashout concrete from ready mix concrete trucks and mixers, for example.

In one embodiment, a method of producing an amorphous silica materialcomprises preparing a batch comprising concrete and melting the batch ina furnace to produce a melt effluent, molten glass, or molten mass. Themethod may comprise additional processing steps to prepare the melteffluent, molten glass, or molten mass (melt effluent) into a product.Therefore, the melt effluent may be subject to further processing suchas, but not limited to, cooling, annealing, quenching to produceparticles or an amorphous mass, air cooling, placing in a mold for a“blow and blow method” or a “press and blow method” for producingcontainer glass, using a gob in the Westlake process, glass blowing(free, mold or modern), floating the melt effluent for flat glass, orother processing steps to produce glass products.

Embodiments of the method comprise making. The method of claim 1,comprising crushing the amorphous silica particles or mass to formparticles. The particles may be used as abrasives media, proppants,frits, or other applications for particles. Additionally, embodiments ofthe method comprise molding the melt effluent, amorphous silicaparticles or mass to form a glass container or other glass article.Further, embodiments of the method may comprise floating the melteffluent to form a sheet of glass, wherein the mass is the sheet ofglass.

The batches may comprise additional components. For example, concretemay be mixed with other components in a batch to provide the desiredproperties to assist in processing and/or product properties such as,but not limited to, melting temperature, melt viscosity, processefficiency, density, toughness, hardness, or other desired properties.

The additional batch components may comprise glass cullet, glass fluxes,at least one metal oxide, at least one metal silicate, at least onemetal, iron oxide, magnetite, calcium containing material, limestone,lime, silica sand, feldspar, metal slags, furnace slags, combustiblematerials, colorants, decolorants, fining agents, oxidizers, andreducers, for example. Calcium containing materials include, but are notlimited to, furnace slag, lignite ash, coal ash, and lime residues fromprocessing, for example.

An embodiment of the method of producing a manufactured glass articlecomprises preparing a batch consisting essentially of concrete. Theembodiment may further comprise melting the batch in a furnace to melteffluent and cooling the melt effluent to form amorphous silicaparticles, mass or product. The batch may further comprise at least oneof colorants, decolorants, fining agents, oxidizers, and reducers.

A further embodiment of the method of producing an amorphous silicamaterial, comprising preparing a batch consisting essentially ofconcrete and glass cullet. Such an embodiment may further compriseadditional steps as described herein and know in the art. A stillfurther embodiment of the method of producing an amorphous silicamaterial comprising preparing a batch consisting essentially ofconcrete, fluxes, and glass cullet.

In another embodiment, a method of producing an amorphous silicamaterial, comprising preparing a batch consisting essentially ofconcrete, sand, limestone, and glass cullet.

Further additional embodiments include a method of producing anamorphous silica material comprising preparing a batch comprisingconcrete, iron oxide, and cullet.

A still further additional embodiment of the method of producing anamorphous silica material comprises preparing a batch consistingessentially of concrete, iron oxide, and cullet.

An embodiment of the method of producing an amorphous silica materialcomprises preparing a batch comprising concrete and metal slag.

The batch may be melted in a furnace to produce furnace effluent or melteffluent. Typically, the batch components will be fed into the furnaceas solids and flow out as a molten liquid. The melt effluent is,typically, a liquid melted glass that flows from the furnace exit. Themelt effluent may be cooled to form a solid amorphous glass by any knownmeans. The cooling means may include, but is not limited to, waterquenching, oil quenching, air cooling, annealing, cooling in a mold,cooling in a float process, and controlled air cooling. Therefore, inany embodiment, a quenching step may be replaced with any other coolingstep as described herein or known in the art. The glass effluent ismerely cooled to form a solid.

In one embodiment, the method comprises quenching the melt effluent toform amorphous silica particles or amorphous silica mass. The quenchingmay be performed by directing the furnace effluent into a water bath asknown in the art.

For some applications, it may be desirable to have the amorphous silicaparticles or amorphous silica mass in different particle sizes. Themethod may further comprise crushing the amorphous silica particles toform particles of the appropriate size for the desired application bymethods known in the art.

Additionally, The glass may undergo further densification process suchas, but not limited to, heat treatments, cold compression, or hotcompression. The densification may occur after quenching or aftercrushing the particles to the desired particle size range, particle sizeaverage or other distribution. Silica glasses may undergo reversible andirreversible amorphous-amorphous transitions under pressure, leading tosome elastic softening upon initial compression and permanentdensification under high pressure. At room temperatures(cold-compression), at pressures above 8-9 GPa, irreversiblepolyamorphic transition takes place and the recovered glass has anincreased density. The same or even higher amount of densification canbe achieved under much lower pressures (4-8 GPa) at high temperatures(hot-compression). Under hot or cold compression, the silica glass maydensify up to about 25%.

Concrete

Embodiments of the method of melting concrete may be used to produceamorphous silica materials including, but not limited to, glass,container glass, fiber glass, glass bead, glass spheres, sheet or plateglass, glass aggregate, glass sand, abrasives, proppants, foamed glass,and manufactured glass articles. The initial processing steps includepreparing a melt batch comprising concrete and, optionally, othercomponents, melting the melt batch, and cooling the melted melt batch.Further processing steps may be utilized to produce the glass article.These finishing processing steps are known in the art and may be appliedas known in the art during the cooling step or in addition to themethod. Such steps are used to produce the glass, container glass, fiberglass, glass bead, glass spheres, sheet or plate glass, glass aggregate,glass sand, abrasives, proppants, foamed glass, and manufactured glassarticles. Typical content of OPCC of approximately 81% SiO2, 13% CaO,<0.7% Fe2O3, and less than 5% aluminum oxide, makes it an effectivefeedstock in varying amounts for nearly all types of glass by balancingtotal oxide contents in the desired finished glass with supplementaloxides from separate sources of silicon dioxide, boron trioxide,aluminum oxide, magnesium oxide, zinc oxide, sodium oxide, potassiumoxide, iron oxide, titanium oxide, etc. These components may be added toa glass batch alone or in combination.

Embodiments of a method of producing a manufactured glass articlecomprise melting a glass batch comprising concrete. Concrete is amixture comprising Portland cement (Types I though V) or blended cement(Types IL, IS, IP, or IT), aggregate (coarse and fine), water ofhydration, and, optionally, admixtures. The admixtures may includemineral (fly ash types F or C, slags), fibers, water reducers, airentraining agents, and rheology modifiers, for example. Other cementsused in concrete include low-iron cements (white cement), andhigh-alumina cements (for example magnesium phosphate).

The concrete in embodiments of the method may be new, waste or recycledconcrete. Recycled concrete being any concrete that has been taken outof service. Waste concrete may be excess concrete or concrete that doesnot meet strength or other required properties for the application andwashout concrete from ready mix concrete trucks and mixers, for example.

In one embodiment, a method of producing an amorphous silica materialcomprises preparing a batch comprising concrete and melting the batch ina furnace to produce a melt effluent, molten glass, or molten mass.Embodiments of a method of producing a manufactured glass articlecomprise melting a glass batch consisting essentially of concrete. Themethods may comprise additional processing steps to prepare the melteffluent, molten glass, or molten mass (melt effluent) into a product.

EXEMPLARY ADDITIONAL COMPONENTS

The additional components may be added to glass batch in anycombination.

Combustible Materials

In some embodiments, the method may comprise adding a combustiblematerial to any of the batches described herein. The combustiblematerial may be any combustible material that undergo combustion at atemperature below the melt temperature of the batch or the processingtemperature. For example, combustible materials include organic matter,cellulosic material, plastics, paper, cloth, natural gas, oils, wood,charcoal, coke, coal, fuels, and combinations thereof.

The combustible material may be added separately or in combination withother components of the batch. For example, charcoal or coke particlesor powders may be premixed in the batch with the other components or bepresent in one of the components of the batch. For example, recycledglass products may comprise combustible materials such as, but notlimited to, paper, plastics, cardboard, oils, food residues, forexample, and may, therefore, may be added to the batch with the recycledglass.

The combustible material may be added to the batch in any desiredconcentration range, for example, the combustible material may be in aconcentration range of above 0 wt. % to 25 wt. %. The combustiblematerial in the batch appears to act to increase the density of theamorphous silica particles. In other embodiments, the combustiblematerial may be added to the batch in a concentration range of above 0.2wt. % to 20 wt. %. In still further embodiments, the combustiblematerial may be added to the batch in a concentration range of above 0.2wt. % to 15 wt. %. In more specific embodiments, the combustiblematerial may be added to the batch in a concentration range of above 0.5wt. % to 8 wt. %.

The addition of the combustible material may improve the properties ofthe amorphous silica particles. The mechanism is not fully understood atthis time, but the results have been confirmed by significantexperimentation. Any of the embodiments described herein may alsocomprise a combustible material in the batch in any concentrationcapable of improving the properties of the amorphous silica production.

Limestone

Limestone and its substitutes have been shown to increase the density ofsome embodiments of the amorphous silica products. Limestone additionsto the batch have also resulted in other improved properties of theamorphous silica particles.

The batches comprising concrete may also comprise limestone or othercalcium containing materials in any concentration that provides thedesired properties in the amorphous silica products. Embodiments of thebatch comprise limestone in concentration of 1 wt. % to 50 wt. %. Infurther embodiments, the limestone may be added to the batch in aconcentration of 1 wt. % to 30 wt. %. In some embodiments, the limestonemay be incorporated in the batch in a concentration of 5 wt. % to 20 wt.%. Limestone may be substituted with other sources of calcium equivalentconcentrations of calcium carbonate or calcium oxides as described.

Therefore, an embodiment of the method of producing an amorphous silicamaterial may comprise preparing a batch comprising concrete andlimestone and melting the batch in a furnace to melt effluent. The batchmay comprise additional optional components in the ranges describedherein.

A further embodiment of the method of producing an amorphous silicamaterial comprising preparing a batch consisting essentially of concreteand melting the batch in a furnace to melt effluent.

A still further embodiment comprising limestone includes a A method ofproducing an amorphous silica material comprises preparing a batchconsisting essentially of concrete, sand, limestone, and glass cullet.The methods may further comprise cooling the melt effluent to formamorphous silica particles, mass or product.

Cullet

Embodiments of the method may comprise preparing a glass batchcomprising concrete and an amorphous silica containing material. Thesources of the amorphous silica containing material include, but are notlimited to, glass cullet, recycled glass, unprocessed glass waste,partially processed glass waste, diatomaceous earth, or combinationsthereof, (herein “cullet”).

Typical Glass Cullet Composition

SiO2 74. wt. % MgO 0.3 wt. % CaO 11.3 wt. % NaO 13 wt. % K2O 0.2 wt. %Al2O3 0.7 wt. % Fe2O3 0.01 wt. %

An embodiment of the method of producing an amorphous silica materialcomprises preparing a batch consisting essentially of concrete and glasscullet. The cullet adds amorphous silica and fluxes, among othercomponents, to the batch. The batch may comprise additional optionalcomponents in the ranges described herein.

A further embodiment of the method of producing an amorphous silicamaterial comprising preparing a batch consisting essentially of concreteand glass cullet. A batch comprising concrete and cullet will melt at alower temperature of a batch consisting essentially of concrete. Tofurther reduce at least one of the melting temperature or the melteffluent viscosity, fluxes may be added to the batch. Therefore, anotherembodiment of the method of producing an amorphous silica materialcomprises preparing a batch consisting essentially of concrete, fluxes,and glass cullet.

Density increasing components may be added to the batch also. As such,an embodiment of the invention comprises a method of producing anamorphous silica material comprises preparing a batch comprisingconcrete, iron oxide, and cullet. The batch may comprise additionalcomponents as described herein or the batch may consist essentially ofconcrete, iron oxide, and cullet.

The batches comprising concrete may also comprise cullet in anyconcentration that provides the desired properties in the amorphoussilica products. Embodiments of the batch comprise cullet inconcentration of 1 wt. % to 80 wt. %. In further embodiments, the culletmay be added to the batch in a concentration of 1 wt. % to 50 wt. %; orin concentration range from 10 wt. % to 50 wt. %. In some embodiments,the cullet may be incorporated in the batch in a concentration of 1 wt.% to 25 wt. %. In other embodiments, the batch may be primarily culletand the cullet may be added in a concentration range from 50 wt. % to 95wt. %.

Flux

The melting point reducing agents may include, but is not limited to,sodium carbonate, sodium nitrate, iron oxide, iron silicates, potash,potassium carbonate, calcium carbonate, colemanite, sodium oxide,calcium oxide, magnesia, alumina, aluminum oxides, alumina silicates,lead oxide, alkali metals, lithium, sodium, potassium, rubidium, cesium,francium, and combinations thereof.

Additional fluxes may include materials such as naturally occurringproducts that contain these reducing agents such as, but not limited to,feldspar, alumina silicates comprising iron, bauxite, clays, ball clays,Kentucky or Tennessee clay, and kaolin, for example. Clay may be afinely-grained natural rock or soil material that combines one or moreclay minerals with possible traces of quartz (SiO2), metal oxides(Al2O3, MgO etc.) and organic matter. Ball clays are typicallykaolinitic sedimentary clays that commonly consist of 20-80% kaolinite,10-25% mica, 6-65% quartz. Another flux may be bauxite. Sodium carbonateincreases the viscosity of the glass melt at a given temperature but isrelatively expensive.

The batches comprising concrete may also comprise at least one flux inany concentration that provides the desired properties in the amorphoussilica products and/or in the processing steps. Embodiments of the batchcomprise flux in concentration of 1 wt. % to 30 wt. %. In furtherembodiments, the flux may be added to the batch in a concentration of 5wt. % to 20 wt. %.

Density, Hardness and Other Property Enhancing Components

Embodiment of the glass batches may comprise at least one of metals,metal silicates, or metal oxides. These metals, metal silicates, andmetal oxides include refractory metals, iron, aluminum, titanium,vanadium, chromium, manganese, zirconium, zircon, niobium, molybdenum,ruthenium, rhodium, hafnium, tantalum, tungsten, rhenium, osmium,iridium, and oxides or silicates of these metals, for example.

The alumina may be from clay and, in some embodiments, low alkali clay.Some clays are up to 10% alumina. Alkalis and lead oxides may decreasehardness in the resultant amorphous product, whereas addition of CaO,MgO, ZnO, Al2O3, B2O3, zirconium, zircon, zirconium oxides, iron andiron oxides may result in amorphous silica products with greaterhardness.

A readily available metal oxide is iron oxide. It has been found thatmagnetite results in a measurable increase in density of the resultantamorphous silica product. As such, a batch comprising concrete mayfurther comprise at least one of at least one of a metal oxide, a metalsilicate, and a metal. The metal oxide, a metal silicate, and a metalmay comprise iron oxide or consist essentially of iron oxide. The ironoxide in any embodiment may be magnetite. Additionally, iron ores may beadded to the batch as a source of iron compounds to produce theamorphous silica products.

The batches comprising concrete may also comprise iron oxide in anyconcentration that provides the desired properties in the amorphoussilica products. Embodiments of the batch comprise iron oxides inconcentration of 1 wt. % to 40 wt. %. In further embodiments, the ironoxides may be added to the batch in a concentration of 10 wt. % to 40wt. %; or in concentration range from 20 wt. % to 40 wt. %.

Embodiments of the batch after melting and cooling may produce amorphoussilica particles have a density greater than 2.65 g/ml and 3.6 g/ml andin some embodiments, a density greater than 2.80 g/ml and less than 4.0g/ml. The amorphous silica particles produced after melting and coolingmay have a density greater than 3.0 g/ml and less than 4.0 g/ml.

Sand

Embodiments of the method may comprise the addition of crystallinesilica compounds to the batch. The most common source of crystallinesilica is silica sand. Though other minerals clays comprise crystallinesilica and may be added.

The crystalline silica addition can increase the silica oxideconcentration in the resultant amorphous silica products. Concrete mayadd a certain amount of silica but this may be supplemented with silicasand.

The batches comprising concrete may also comprise silica sand or asource of crystalline silica in any concentration that provides thedesired properties in the amorphous silica products. Embodiments of thebatch comprise silica sand or a source of crystalline silica inconcentration of 1 wt. % to 30 wt. %. In further embodiments, the silicasand or a source of crystalline silica may be added to the batch in aconcentration of 5 wt. % to 20 wt. %; or in concentration range from 20wt. % to 40 wt. %.

Mineral Slags

Mineral slags comprise silica compounds and other metal oxides and,therefore, they may be used in embodiments of the methods. Such slagsmay comprise components above acceptable limits by industrial hygieneorganizations. In embodiments of the invention, glass cullet, sand,and/or additional oxides such as, iron oxide, aluminum oxide, titaniumoxide and zirconium oxide, for example, may be added to the batchcomprising concrete to produce an amorphous silica product having thepotentially toxic components below the acceptable limits. Mineral slagincluding, but not limited to, iron slag, nickel slag, copper slag,platinum slag, and coal slag, may also be blended into a batch toproduce an amorphous silica product. The mineral slags may be combinedwith any of the components as described herein including, but notlimited to, silica sand, glass cullet, recycled Portland concrete, ironore or iron oxides, limestone, combustible materials, fluxes, and/or thesubstitutes for these materials as described herein.

The batches comprising concrete may also comprise silica sand or asource of crystalline silica in any concentration that provides thedesired properties in the amorphous silica products. Embodiments of thebatch comprise silica sand or a source of crystalline silica inconcentration of 1 wt. % to 30 wt. %. In further embodiments, the silicasand or a source of crystalline silica may be added to the batch in aconcentration of 5 wt. % to 20 wt. %; or in concentration range from 20wt. % to 40 wt. %.

Preparing the Glass Batch, Batch, or Melt Composition

Embodiments of the method comprise preparing a glass batch. The glassbatches are based upon concrete such as, but not limited to, recycledPortland cement concrete. The concrete may be melted alone or with anyof the components or combinations of these components.

Recycled Portland Cement Concrete

In one embodiment, the glass batch may comprise or consist essentiallyof recycled Portland cement concrete. The glass batch may comprise 40wt. % to 70 wt. % recycled Portland cement concrete, 30 wt. % to 35 wt.% iron oxide, preferably magnetite, 0 wt % to 10 wt. % limestone, and 0%to 5% combustible material, preferably charcoal.

Combinations of Recycled Portland Cement Concrete and Amorphous Silicaand Crystalline Silica

In some embodiments, the glass batch may be a combination of recycledPortland cement concrete, silica sand, or recycled glass cullet. Theglass batch may comprise cement concrete, 5 wt. % to 10 wt. % recycledglass cullet or 5 wt. % to 10 wt. % silica sand, 30 wt. % to 35 wt. %iron oxide, or more preferably magnetite, and 0 wt. % to 5 wt. %combustible material, preferably charcoal.

Combinations of Recycled Portland Cement Concrete and Mineral Slag

In some embodiments, the glass batch may be a combination of recycledPortland cement concrete and mineral slag. The glass batch may comprise1 wt. % to 70 wt. % recycled Portland cement concrete, 1 wt. % to 70 wt.% mineral slag (coal slag, copper slag, nickel slag, iron slag, orsimilar), and 0 wt. % to 40 wt. % iron oxide, preferably magnetite, and0 wt. % to 5 wt % combustible material, preferably charcoal.

By processing the glass batches in either glass manufacturing methods orfrit manufacturing methods, amorphous glass products will be produced.The amorphous glass may be used for any purpose including, but notlimited to, abrasive blasting media, proppants, high density amorphousglass product, and other products.

Heating the Glass Batch to produce amorphous silica products

Embodiments of the method comprise converting crystalline silica into anamorphous silica produce amorphous silica sand, gravel, or otherparticles, sheets, or fibers. The method may comprise heating the glassbatch comprising crystalline silica in the concrete, for example, to atemperature above the temperature that results in the phase change fromthe crystalline silica to an amorphous form of silica. The furnace mayincrease the temperature of the glass batch above the meltingtemperature of crystalline silica. The melting point of pure silicadioxide is 3110° F. (1710° C.) but may be lowered by addition of fluxesas described above.

Embodiments of the heating the glass batch comprise feeding the glassbatch into a glass melting furnace. The furnace may be a continuous orbatch furnace. There are various types of glass melting furnacesincluding pot furnaces (for batch processing), day tank furnaces, gasfired furnaces, and electric furnaces.

In an embodiment comprising a continuous furnace, the glass batch may beheated to and become molten at approximately 1100° C. to 1700° C., morespecifically a temperature range 1250° C. to 1600° C., depending uponthe composition of the glass batch. In some embodiments of the method,the glass batch may be heated to or above the melt temperature of theglass batch. In another embodiment, the glass batch may be heated to atemperature between the melt temperature and the temperature in whichthe crystalline silica converts to amorphous silica. As previouslydescribed, the melt temperature and the temperature at which thecrystalline silica converts to amorphous silica will depend on thecomposition of the glass batch. In such embodiments, the glass batch maybe heated to a temperature below the gob temperature. In certain batchembodiments, the glass batch may be heated to similar temperatures. Incertain embodiments, the process does not comprise refining the moltenglass batch to remove all gas bubbles. This process is necessary toproduce clear glass containers or plate glass but may not be necessaryto produce amorphous silica sand, gravel, and other particles, sheets,or fibers.

The melt effluent of the furnace may be a ribbon of molten amorphoussilica.

Cooling the Furnace Effluent

Embodiments of the method of the invention comprise cooling the ribboneffluent from the furnace. Therefore, a method may comprise cooling orallowing the amorphous mass cool to a hardened state. In someembodiments, the process may comprise rapidly cooling or quenching theribbon of furnace effluent such as by fritting. Fritting of the moltenglass causes a thermal gradient and violent fracturing of thesolidifying amorphous material. The quenching of the molten glass may beperformed by contact with a fluid such as water. The molten glass ribbonmay overflow the furnace into a bath of fluid or the fluid may bespraying of the molten glass.

The solidified solid is an amorphous silica product. The fracturing ofthe glass results in small particles that may be classified intoparticle size ranges. The various particle size ranges may findapplication in the products described herein.

Embodiments of the method may further comprise crushing or otherwisecomminuting at least a portion of the amorphous silica to particles to asmaller size or to narrow the particle size distribution. The desiredparticle size distribution may be the appropriate particle sizedistribution for abrasive blasting, use in mortar, plaster, concrete,and asphalt paving, foundry sand, and/or the production of bricks, forexample.

Optionally, an embodiment of the process may comprise annealingfractured amorphous silica particle or the crushed or otherwisecomminuted amorphous mass.

The molten glass batch exits the refractory through a weir. The weir isdesigned to provide an evenly shaped flow of molten glass for quenching.The furnace may have more than one weir to ensure proper molten glassribbon shape and size for efficient quenching and fracturing of thesolidifying amorphous silica.

In certain embodiments, quenching the molten amorphous mass should beperformed properly to ensure fracturing of the amorphous solid uponrapid cooling. Ideally, the quenched amorphous solid comprises aparticulate product having a desired particle size range, averageparticle size, and/or particle size distribution. The furnace effluentflow rate and shape may be controlled to provide uniform quenching ofthe amorphous silica.

Applications and Products

An embodiment of a process consists essentially of transforming concreteinto amorphous silica melt effluent, sand, gravel or other particles forthe purpose of rendering the material substantially free of crystallinesilica making it a safe replacement for naturally occurring productscontaining various forms of crystalline silica in consumer andindustrial applications through a process comprising heating thecrystalline or polycrystalline sand, grains, particles or rock into anamorphous mass and reducing the size of the amorphous mass for use inthe desired application.

Still further embodiments of the process may comprise using amorphoussand for applications that currently of previously used crystalline orpolycrystalline sand products including, but not limited to silica sandproduct applications and crushed rock products.

The amorphous sand, products, and articles produced by this process areespecially useful for processes that produce airborne dusts and productssuch as for abrasive blasting or products that will be cut such ascement blocks, pavers, or bricks to avoid producing a potentiallydangerous dust if crystalline silica sand was used, or are useful inrecycling, repurposing, or otherwise transforming materials that mightotherwise be destined to landfills into products of value.

Products and applications for the amorphous silica particles include butare not limited to, crystalline silica free amorphous silica sand,crystalline silica free amorphous silica gravel, crystalline silica freeamorphous cullet or feedstock, amorphous silica blasting material,crystalline silica free concrete, grout, manufactured stone, pavers, ormortar, concrete blocks made from crystalline silica free concrete,crystalline silica free bricks comprising crystalline free amorphoussilica, crystalline silica free glass sheets, containers, andcrystalline silica free glass fibers. For example, the bricks maycomprise crystalline silica free sand in a concentration from 50% to 60%by weight, alumina in a concentration from 20% to 30% by weight, andlime in a concentration from 2 to 5% by weight.

As such, an embodiment of the amorphous silica product comprisesamorphous silicon oxide in the range of 50 wt. % to 75 wt. %, acombination of iron oxides and aluminum oxides, wherein the iron oxidesand the aluminum oxides together are in in the range of 15 wt. % to 50wt. %, wherein the aluminum oxides are in a range of 0.5 wt. % to 10 wt.%., and fluxing compounds in the range of 0 to 10 wt. %. In a morespecific embodiment, the aluminum oxides may be in the range of 3 to 10wt. %.

Similarly, an embodiment of the amorphous silica product comprisesamorphous silicon oxide in the range of 50 wt. % to 75 wt. %, acombination of iron oxides and zirconium oxides, wherein the iron oxidesand the zirconium oxides together are in in the range of 12 wt. % to 50wt. %, wherein the zirconium oxides are in a range of 0.5 wt. % to 10wt. %., and fluxing compounds in the range of 0 to 10 wt. %. In a morespecific embodiment, the aluminum oxides may be in the range of 0.5 wt.% to 5 wt. %. In either of the above embodiments, the zirconium oxidesor the aluminum oxides may be substituted with a combination of aluminumoxides and zirconium oxides.

Other embodiments of the amorphous silica product comprises unusuallylow levels of silicon in the form of amorphous silicon oxide in therange of 13 wt. % to 25 wt %, iron oxides in the range of 0% wt. % to 40wt. %, Aluminum oxides in the range of 0 wt. % to 12 wt. %, magnesiumoxides in the range of 0 wt. % to 3 wt. %, calcium oxides in the rangeof 8 wt. % to 25 wt %., alkali metals in the range of 0 wt. % to 1 wt.%, and carbon in the range of 0 wt. % to 10 wt. %. Such products exhibitexcellent levels of density, often above 3.0 g/cm3, and favorablehardness for their applications, often in a range of 500 to 640 KnoopHardness.

Further, an embodiment of the amorphous silica product consistsessentially of amorphous silicon oxide in the range of 10 wt. % to 60wt. %, a combination of iron oxides and calcium oxides, wherein the ironoxides and the calcium oxides together are in in the range of 15 wt. %to 85 wt. %, and fluxing compounds in the range of 0 to 20 wt. %. Inanother such embodiments, the iron oxides may be in a concentrationrange of 10 wt. % to 60 wt. %. In another embodiment, the iron oxidesmay be in a concentration range of 20 wt. % to 50 wt. % and the calciumoxides may be in a concentration range of 10 wt. % to 45 wt. %. In afurther embodiment, the iron oxides may be in a concentration range of20 wt. % to 40 wt. % and the calcium oxides may be in a range of 20 wt.% to 40 wt. %. The amorphous silica of the invention may be used aswater insoluble or water soluble sand and blasting media. In a morespecific embodiment, the iron oxides may be in the range of 25 to 40 wt.%.

Unlike recycled glass products, the amorphous silica sand produced bythe method of the invention will comprise no non-glass residues (trashor contaminants) such as trace fecal matter, trace ferrous items ormatter (unless intentionally added), trace nonferrous items or metals,trace stone or ceramic items or matter, and/or trace pathogens. Thesesubstances are found in all recycled glass cullet products.

Another embodiment of the method of the present invention to directlycreate a glass cullet that is free from contaminants. Glass productionfacilities add crushed recycled glass cullet into the new glassproduction process to reduce the heat required to melt the silica sandand the melt temperature of the silica sand. The problem with this glasscullet is that it may include contaminants from the glass recycleprocess. An embodiment of the method of the present invention is toproduce clean glass cullet directly from concrete. This “pre-reacted”batch material that can be added to batch glass (much as glass cullet isused today) that will lower the melt temperature of batch glass.

The amorphous silica sand, gravel, products, articles or other particlesmay be used in the manufacture of many products. For example,crystalline free silica foam glass and ceramics may be produced. Anembodiment of the method for production of crystalline free foamed glassmay comprise blending fine amorphous silica sand or ground amorphoussilica sand with a blowing agent to form a foam glass precursor. Theblowing agent may be any compound that produces an off-gas duringheating at furnace temperatures. The blowing agent may be, but is notlimited to, carbon or limestone, for example.

The method may further comprise heating the foam glass precursor in thefurnace to cause the blowing agents to out-gas, thus expanding orfoaming the molten mass. The molten mass is cooled and annealed tofreeze the gas pockets creating a lightweight product. Foamed glass inthe melted state can be formed into many products including insulation,blocks, brick, or aggregate for construction or agriculture.

The new “virgin” amorphous silica glass cullet product would competedirectly with recycled glass cullet. The advantage of the embodied“pre-reacted” batch material would be it would be 100% free ofdeleterious materials such as rock, ceramic, metals, or lead that culletproducers go to a lot of work to ensure don't get into their cullet inexcessive quantities.

As used herein, the term “no trace” means that the component is belowmeasurement limits of instruments typically used to determine theconcentration of the component.

As used herein, “amorphous silica sand” means a silica productcomprising less than 2 wt. % of crystalline silica in a primarilyamorphous silica product, in a more specific embodiment, “amorphoussilica sand” means a silica product comprising less than 1 wt. % ofcrystalline silica in a primarily amorphous silica product; and in aneven more specific embodiment for blasting products, for example,“amorphous silica sand” means a silica product comprising less than 0.5wt. % of crystalline silica in a primarily amorphous silica product.

EXAMPLES

Cullet was obtained from a glass recycling facility. The composition ofthe cullet was approximately as follows:

In embodiments of the glass formulations, the silicon oxides may beadded in the form of cullet, sand, other sources of silicon oxides, orcombinations thereof.

The melts were performed in a [Make and Model of Furnace] CF1700 mufflefurnace manufactured by Across International.

Example 1

A melt batch (Sample 2789) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 85 wt. %, sodium oxide (NaO) at 14wt. %, and iron oxide (Fe2O3) at 1 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1525° C. The melted batch was then quenched in water. Thesolidified glass was sent for analysis for specific gravity andhardness. The specific gravity was determined to be 2.25. The Knoophardness was determined to be 481.8.

Example 2

A melt batch (Sample 2790) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 84 wt. %, zirconium oxide (ZrO) at13 wt. %, sodium oxide (NaO) at 1 wt. %, and iron oxide (Fe2O3) at 2 wt.% in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1550° C. The melted batch was then quenched in water. Thesolidified glass was sent for analysis for specific gravity andhardness. The specific gravity was determined to be 2.36. The Knoophardness was determined to be 493.7.

Example 3

A melt batch (Sample 2791) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 83 wt. %, zirconium oxide (ZrO) at2 wt. %, sodium oxide (NaO) at 10 wt. %, and iron oxide (Fe2O3) at 5 wt.% in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1575° C. The melted batch was then quenched in water. Thesolidified glass was sent for analysis for specific gravity andhardness. The specific gravity was determined to be 2.35. The Knoophardness was determined to be 540.6.

Example 4

A melt batch (Sample 2792) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 80 wt. %, zirconium oxide (ZrO) at5 wt. %, sodium oxide (NaO) at 5 wt. %, and iron oxide (Fe2O3) at 10 wt.% in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1625° C. The melted batch was then quenched in water. Thesolidified glass was sent for analysis for specific gravity andhardness. The specific gravity was determined to be 2.86. The Knoophardness was determined to be 638.4.

Example 5

A melt batch (Sample 2799) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 70 wt. %, zirconium oxide (ZrO) at2 wt. %, sodium oxide (NaO) at 5 wt. %, aluminum oxide (Al2O3) at 3 wt.%, and iron oxide (Fe2O3) at 20 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1600 to 1625° C. The melted batch was then quenched inwater. The solidified glass was sent for analysis for specific gravityand hardness. The specific gravity was determined to be 2.5. The Knoophardness was determined to be 615.4.

Example 6

A melt batch (Sample 2800) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 65 wt. %, zirconium oxide (ZrO) at2 wt. %, sodium oxide (NaO) at 4 wt. %, aluminum oxide (Al2O3) at 6 wt.%, and iron oxide (Fe2O3) at 23 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1600 to 1625° C. The melted batch was then quenched inwater. The solidified glass was sent for analysis for specific gravityand hardness. The specific gravity was determined to be 2.69. The Knoophardness was determined to be 668.7.

Example 7: Melt Batch from Sand

A melt batch (Sample 2801) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 60 wt. %, zirconium oxide (ZrO) at2 wt. %, sodium oxide (NaO) at 3 wt. %, aluminum oxide (Al2O3) at 8 wt.%, and iron oxide (Fe2O3) at 27 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1600 to 1625° C. The melted batch was then quenched inwater. The solidified glass was sent for analysis for specific gravityand hardness. The specific gravity was determined to be 2.52. The Knoophardness was determined to be 721.9.

Example 8: Melt Batch from Cullet

A melt batch (Sample 2802) was prepared comprising the followingcomposition, cullet (approximate composition above) at 90 wt. %,zirconium oxide (ZrO) at 2 wt. %, aluminum oxide (Al2O3) at 3 wt. %, andiron oxide (Fe2O3) at 5 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1600 to 1625° C. The melted batch was then quenched inwater. The solidified glass was sent for analysis for specific gravityand hardness. The specific gravity was determined to be 2.50. The Knoophardness was determined to be 622.

Example 9: Melt Batch from Cullet

A melt batch (Sample 2803) was prepared comprising the followingcomposition, cullet (approximate composition above) at 80 wt. %,zirconium oxide (ZrO) at 3 wt. %, aluminum oxide (Al2O3) at 4.5 wt. %,and iron oxide (Fe2O3) at 12.5 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1600 to 1625° C. The melted batch was then quenched inwater. The solidified glass was sent for analysis for specific gravityand hardness. The specific gravity was determined to be 2.54. The Knoophardness was determined to be 651.9.

Example 10: Melt Batch from Cullet

A melt batch (Sample 2804) was prepared comprising the followingcomposition, cullet (approximate composition above) at 70 wt. %,zirconium oxide (ZrO) at 4 wt. %, aluminum oxide (Al2O3) at 6 wt. %, andiron oxide (Fe2O3) at 20 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately 1600 to 1625° C. The melted batch was then quenched inwater. The solidified glass was sent for analysis for specific gravityand hardness. The specific gravity was determined to be 2.71. The Knoophardness was determined to be 654.8.

Example 11: Melt Batch from Sand

A melt batch (Sample 2809) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 62.45 wt. %, magnesium oxide (MgO)at 0.3 wt. %, calcium oxide (CaO) at 0.2 wt. %, sodium oxide (NaO) at 7wt. %, potassium oxide (KO) at 0.05 wt. %, and iron oxide (Fe2O3) at 30wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately YYYY® C. A portion of the melted batch was then quenchedin water (Sample XXXXQ) and a portion of the melted batch was air cooled(Sample 2809A).

The solidified glass was sent for analysis for specific gravity andhardness. The specific gravity for Sample 2809Q was determined to be2.534 and its Knoop hardness was determined to be 552.1.

The specific gravity for Sample 2809A was determined to be 2.864 and itsKnoop hardness was determined to be 570.6.

Example 12: Melt Batch from Sand

A melt batch (Sample 2810) was prepared comprising the followingcomposition, silica dioxide (SiO2) at 57.45 wt. %, magnesium oxide (MgO)at 0.3 wt. %, calcium oxide (CaO) at 0.2 wt. %, sodium oxide (NaO) at6.14 wt. %, potassium oxide (KO) at 0.05 wt. %, and iron oxide (Fe2O3)at 35 wt. % in the melt batch.

The melt batch was melted in a crucible in a batch furnace atapproximately YYYY® C. A portion of the melted batch was then quenchedin water (Sample 28100) and a portion of the melted batch was air cooled(Sample 2810A).

The solidified glass was sent for analysis for specific gravity andhardness. The specific gravity for Sample 28100 was determined to be2.858 and its Knoop hardness was determined to be 580.8.

The specific gravity for Sample 2810A was determined to be 2.826 and itsKnoop hardness was determined to be 586.4.

Example 12

A melt batch may be prepared comprising the following composition,silica dioxide (SiO2) at 42.3 wt. %, magnesium oxide (MgO) at 0.3 wt. %,calcium oxide (CaO) at 0.2 wt. %, sodium oxide (NaO) at 6.14 wt. %, wt.%, and iron oxide (Fe2O3) at 50 wt. % in the melt batch.

FURTHER EXAMPLES

Additional amorphous silica products were produced from batches asdescribed in the tables below. The examples exemplify the methods usedto produce the amorphous silica products from crystalline silica,amorphous silica and combinations of amorphous and crystalline silica.

The examples demonstrate the use of iron oxides and/or limestone cancheaply increase the density of these products over the silica sand andcullet.

Primary Network Former: Cullet

Crucible: Alumina or Graphite

Iron (III) Melt Specific Knoop Temp. Oxide Magne- Iron Ore Calcium Lime-Sodium Potassium Char- # Gravity Hardness ° C. Crucible Cullet Fe2O3tite (Taconite) Carbonate stone Carbonate Carbonate coal 108 2.67 1200Alumina 65.00% 30.00% 0.00% 5.00% 0.00% 0.00% 109 2.70 1200 Alumina68.00% 32.00% 0.00% 0.00% 0.00% 0.00% 111 2.77 539.4 1200 Alumina 65.00%30.00% 3.00% 0.00% 0.00% 2.00% 112 2.80 554.1 1290 Alumina 65.00% 30.00%0.00% 5.00% 0.00% 0.00% 41 2.74 589.8 1290 Alumina 65.00% 30.00% 0.00%0.00% 5.00% 0.00% 41 2.68 1200 Alumina 65.00% 30.00% 0.00% 0.00% 5.00%0.00% 41 2.69 1290 Alumina 65.00% 30.00% 0.00% 0.00% 5.00% 0.00% 43 2.701280 Alumina 66.67% 28.57% 0.00% 0.00% 4.76% 0.00% 45 2.78 1290 Alumina46.00% 30.00% 0.00% 12.00% 12.00% 0.00% 47 2.77 1290 Alumina 26.00%29.00% 0.00% 36.40% 8.60% 0.00% 51 2.72 1290 Alumina 30.00% 30.00%30.00% 0.00% 0.00% 10.00% 94 2.72 1290 Alumina 68.00% 32.00% 0.00% 0.00%0.00% 0.00% 110 2.70 1200 Alumina 65.00% 0.00% 30.00% 3.00% 2.00% 952.78 1380 Alumina 63.00% 0.00% 32.00% 0.00% 5.00% 96 2.67 1290 Alumina63.00% 32.00% 0.00% 0.00% 5.00% 103 2.78 1290 Alumina 63.00% 0.00%32.00% 0.00% 5.00% 104 2.81 530.8 1290 Alumina 63.00% 0.00% 32.00% 3.00%2.00% 113 2.81 1390 Alumina 63.00% 0.00% 31.00% 4.00% 2.00% 114 3.011390 Alumina 65.00% 0.00% 30.00% 3.00% 2.00% 85 2.64 1380 Alumina 20.08%35.66% 0.00% 36.43% 0.00% 7.83% 0.00% 91 3.24 1390 Alumina 18.78% 0.00%33.35% 34.07% 0.00% 7.32% 6.48% 99 2.69 1480 Alumina 23.64% 0.00% 26.36%33.09% 7.82% 0.00% 9.09% 105 3.18 473.2 1390 Alumina 24.64% 0.00% 30.45%33.09% 7.82% 0.00% 4.00% 42 2.73 1380 Alumina 49.00% 33.00% 6.00% 0.00%12.00% 0.00% 22 3.07 646.2 1380 Alumina 18.78% 33.35% 34.07% 0.00% 7.32%6.48% 23 3.02 1380 Alumina 25.00% 50.00% 13.00% 0.00% 12.00% 0.00% 312.95 533.1 1430 Alumina 27.92% 26.34% 37.65% 0.00% 8.09% 0.00% 32 2.97567.3 1380 Alumina 27.97% 26.27% 37.66% 0.00% 8.09% 0.00% 33 2.93 1380Alumina 26.00% 29.00% 36.43% 0.00% 8.57% 0.00% 34 2.89 1380 Alumina22.37% 29.01% 34.61% 0.00% 7.43% 6.58% 35 2.87 1380 Alumina 43.00%26.00% 19.00% 12.00% 0.00% 0.00% 36 2.87 576.8 1380 Alumina 55.00%40.00% 0.00% 0.00% 5.00% 0.00% 37 2.85 1290 Alumina 25.40% 30.30% 34.30%0.00% 10.00% 0.00% 38 2.83 1380 Alumina 43.00% 26.00% 19.00% 0.00%12.00% 0.00% 39 2.79 1380 Alumina 45.00% 30.00% 13.00% 0.00% 12.00%0.00% 40 2.76 1380 Alumina 50.00% 38.00% 0.00% 0.00% 12.00% 0.00% 1 2.541409 Graphite 60.00% 40.00% 0.00% 2 2.44 1450 Graphite 70.00% 30.00%0.00% 3 2.32 1450 Graphite 80.00% 20.00% 0.00% 4 2.45 1450 Graphite90.00% 10.00% 0.00% 20 3.13 1380 Graphite 26.05% 0.00% 24.58% 35.14%0.00% 7.55% 6.68% 21 3.13 1380 Graphite 27.92% 0.00% 26.34% 37.65% 0.00%8.09% 0.00%

Primary Network Former: Silica Sand

Crucible: Alumina

Melt Specific Knoop Iron (III) Sodium Potassium # Gravity Hardness Temp.° C. Crucible Sand Oxide Fe2O3 Magnetite Limestone Carbonate CarbonateCharcoal 86 2.67 1480 Alumina 14.57% 34.52% 0.00% 33.31% 4.43% 7.16%6.02% 87 3.10 1480 Alumina 14.57% 34.52% 0.00% 33.31% 4.43% 7.16% 6.02%88 3.16 1480 Alumina 14.57% 0.00% 34.52% 33.31% 4.43% 7.16% 6.02% 893.23 585.5 1390 Alumina 14.57% 0.00% 34.52% 33.31% 4.43% 7.16% 6.02% 1003.23 1390 Alumina 15.50% 0.00% 36.74% 35.44% 4.71% 7.61% 0.00% 106 3.081390 Alumina 15.50% 0.00% 36.73% 35.45% 4.72% 7.61% 0.00% 90 3.35 617.61390 Alumina 10.20% 4.37% 34.52% 33.31% 4.43% 7.16% 6.02% 93 3.32 1390Alumina 10.20% 4.37% 34.52% 33.31% 4.43% 7.16% 6.02%

Primary Network Former: Silica Sand or Cullet, and Mineral Slag

Crucible: Alumina

Melt Specific Knoop Magnesium Calcium # Gravity Hardness Temp. ° C.Crucible Sand Cullet Coal Slag Nickel Slag Magnetite Oxide CarbonateLimestone 58 2.82 1390 Alumina 20.00% 0.00% 60.00% 15.00% 0.00% 5.00%0.00% 62 2.63 1480 Alumina 40.00% 50.00% 0.00% 5.00% 0.00% 5.00% 0.00%64 2.87 1480 Alumina 10.00% 0.00% 50.00% 30.00% 0.00% 10.00% 0.00% 652.54 1480 Alumina 20.00% 50.00% 0.00% 5.00% 10.00% 0.00% 15.00% 73 2.841480 Alumina 19.05% 47.62% 0.00% 23.81% 0.00% 0.00% 9.52% 75 2.77 1390Alumina 19.05% 57.14% 0.00% 14.29% 0.00% 0.00% 9.52% 117 2.98 1390Alumina 11.00% 50.00% 0.00% 25.00% 0.00% 0.00% 14.00% 118 2.89 1390Alumina 9.00% 60.00% 0.00% 22.00% 0.00% 0.00% 9.00% 119 3.01 1480Alumina 12.00% 0.00% 50.00% 20.00% 0.00% 0.00% 18.00% 120 2.88 1480Alumina 15.00% 0.00% 60.00% 15.00% 0.00% 0.00% 10.00% 121 2.95 725.81480 Alumina 11.00% 50.00% 25.00% 14.00% 122 2.88 1480 Alumina 12.00%50.00% 20.00% 18.00%

Primary Network Former: Silica Sand or Cullet and Recycled Concrete

Crucible: Alumina

Melt Specific Knoop Temp. Recycled Sodium # Gravity Hardness ° C.Crucible Sand Cullet Concrete Magnetite Limestone Carbonate Charcoal 1232.73 1480 Alumina 0.00% 10.00% 40.00% 35.00% 15.00% 0.00% 135 2.87 1480Alumina 0.00% 9.50% 38.00% 33.25% 14.25% 5.00% 136 3.10 679.1 1390Alumina 10.00% 0.00% 40.00% 35.00% 15.00% 0.00% 139 3.12 625.9 1390Alumina 0.00% 0.00% 60.00% 30.00% 5.00% 5.00% 137 2.76 1290 Alumina0.00% 0.00% 60.00% 30.00% 5.00% 5.00% 138 3.08 1290 Alumina 0.00% 5.00%60.00% 30.00% 5.00% 0.00% 140 2.75 618.0 1490 Alumina 0.00% 5.00% 70.00%10.00% 10.00% 5.00% 141 2.59 614.2 1490 Alumina 0.00% 0.00% 100.00%0.00% 1.00% 0.00% 142 2.76 1390 Alumina 0.00% 0.00% 60.00% 30.00% 4.00%5.00% 147 2.33 1490 Alumina 0.00% 0.00% 96.00% 0.00% 0.00% 4.00% 0.00%148 2.28 1490 Alumina 0.00% 0.00% 94.00% 0.00% 0.00% 6.00% 0.00% 1492.42 1390 Alumina 0.00% 0.00% 92.00% 0.00% 0.00% 8.00% 0.00% 150 2.82517.5 1390 Alumina 0.00% 10.20% 51.02% 30.61% 0.00% 8.16% 0.00% 151 2.77551.6 1390 Alumina 0.00% 20.40% 40.82% 30.61% 0.00% 8.16% 0.00% 152 2.78581.9 1390 Alumina 0.00% 30.61% 30.61% 30.61% 0.00% 8.16% 0.00% 152 2.78581.9 1390 Alumina 0.00% 30.61% 30.61% 30.61% 0.00% 8.16% 0.00% 154 2.911290 Alumina 0.00% 5.00% 60.00% 30.00% 5.00% 0.00% 0.00% 155 2.83 1290Alumina 0.00% 10.00% 50.00% 25.00% 5.00% 10.00% 0.00% 156 2.56 1290Alumina 0.00% 15.00% 50.00% 15.00% 10.00% 10.00% 0.00% 157 2.70 1290Alumina 0.00% 17.25% 47.50% 10.00% 15.00% 10.00% 0.00%

Recycled Concrete

Crucible: Alumina

Melt Specific Knoop Temp. Recycled Manganese Sodium Sodium # GravityHardness ° C. Crucible Sand Cullet Concrete Dioxide Limestone CarbonateSulfate 158 z z 1490 Alumina 0.00% 5.00% 86.00% 1.00% 0.00% 8.00% 0.00%159 1490 Alumina 0.00% 10.00% 81.50% 0.50% 0.00% 8.00% 0.00% 160 1490Alumina 0.00% 15.00% 76.50% 0.25% 0.00% 8.00% 0.00% 161 1490 Alumina0.00% 14.75% 76.50% 0.50% 0.00% 8.00% 0.00% 162 1490 Alumina 0.00%20.00% 71.75% 0.25% 0.00% 8.00% 0.00% 163 1490 Alumina 0.00% 25.00%66.75% 0.25% 0.00% 8.00% 0.00% 164 1490 Alumina 0.00% 30.00% 61.75%0.25% 0.00% 8.00% 0.00% 165 1490 Alumina 0.00% 35.00% 56.00% 1.00% 0.00%8.00% 0.00% 167 1490 Alumina 0.00% 44.00% 46.00% 1.00% 0.00% 8.00% 1.00%168 1490 Alumina 0.00% 54.00% 36.00% 1.00% 0.00% 8.00% 1.00% 169 1490Alumina 0.00% 64.00% 26.00% 1.00% 0.00% 8.00% 1.00% 170 1490 Alumina0.00% 74.00% 16.00% 1.00% 0.00% 8.00% 1.00% 171 1490 Alumina 0.00%80.00% 10.00% 1.00% 0.00% 8.00% 1.00% 172 1490 Alumina 0.00% 15.00%76.75% 0.25% 0.00% 8.00% 1.00%

Primary Network Former: Cullet and Alumina

Crucible: Graphite or Alumina

Iron (III) Melt Specific Oxide Recycled Calcium Potassium SodiumPotassium # Gravity Temp. ° C. Crucible Cullet Alumina Fe2O3 Iron/SteelOxide Sulfate Carbonate Sulfate Charcoal 7 2.73 1400 Graphite 60.70%3.10% 30.10% 0.00% 0.00% 6.10% 0.00% 0.00% 8 2.76 1400 Graphite 58.70%5.10% 30.10% 0.00% 0.00% 6.10% 0.00% 0.00% 9 2.79 1400 Graphite 53.70%5.10% 30.10% 0.00% 5.00% 6.10% 0.00% 0.00% 10 2.69 1380 Graphite 36.80%3.10% 45.00% 0.00% 5.00% 6.10% 4.00% 6.10% 0.00% 11 2.64 1380 Graphite53.70% 5.10% 22.00% 6.00% 7.10% 6.10% 0.00% 6.10% 0.00% 12 2.74 1380Graphite 53.70% 5.10% 29.10% 1.00% 5.00% 6.10% 0.00% 6.10% 0.00% 13 2.691380 Graphite 53.70% 5.10% 30.10% 0.00% 5.00% 6.10% 0.00% 6.10% 0.00% 142.63 1380 Graphite 53.70% 5.10% 30.10% 0.00% 5.00% 0.00% 6.10% 0.00%0.00% 15 2.71 1380 Graphite 53.70% 5.10% 29.10% 0.00% 5.00% 6.10% 0.00%6.10% 1.00% 16 2.71 1380 Graphite 53.70% 5.10% 29.10% 0.00% 5.00% 6.10%0.00% 6.10% 1.00% 17 2.76 1380 Graphite 53.70% 5.10% 29.10% 0.00% 5.00%6.10% 0.00% 6.10% 1.00% 18 2.75 1380 Graphite 53.70% 5.10% 29.10% 0.00%5.00% 6.10% 0.00% 6.10% 1.00% 19 2.79 1380 Graphite 53.70% 5.10% 29.10%0.00% 5.00% 6.10% 0.00% 6.10% 1.00%

Primary Network Former: Cullet and Iron-Alumina Silicate (Garnet)

Crucible: Graphite or Alumina

Melt Specific Knoop Iron (III) Sodium Potassium # Gravity Hardness Temp.° C. Crucible Cullet Garnet Oxide Fe2O3 Carbonate Sulfate Charcoal 52.66 1400 Graphite 53.50% 13.13% 24.81% 0.00% 8.56% 0.00% 6 2.74 1400Graphite 47.18% 22.86% 21.40% 0.00% 8.56% 0.00% 84 2.67 667.4 1480Alumina 95.00% 5.00%

The embodiments of the described amorphous silica products and methodare not limited to the particular embodiments, components, method steps,and materials disclosed herein as such components, process steps, andmaterials may vary. Moreover, the terminology employed herein is usedfor the purpose of describing exemplary embodiments only and theterminology is not intended to be limiting since the scope of thevarious embodiments of the present invention will be limited only by theappended claims and equivalents thereof.

Therefore, while embodiments of the invention are described withreference to exemplary embodiments, those skilled in the art willunderstand that variations and modifications can be affected within thescope of the invention as defined in the appended claims. Accordingly,the scope of the various embodiments of the present invention should notbe limited to the above discussed embodiments and should only be definedby the following claims and all equivalents.

1. A method of producing an amorphous silica material, comprising:preparing a batch comprising concrete; melting the batch in a furnace tomelt effluent; and cooling the melt effluent to form a glass containeror other molded glass article. 2.-4. (canceled)
 5. The method of claim1, wherein the batch comprises glass cullet.
 6. (canceled)
 7. The methodof claim 1, wherein the batch comprises at least one flux.
 8. The methodof claim 5, wherein the glass cullet is in a concentration range from 1wt. % to 95 wt. %.
 9. The method of claim 5, wherein the glass cullet isin a concentration range from 1 wt. % to 80 wt. %.
 10. The method ofclaim 5, wherein the glass cullet is in a concentration range from 1 wt.% to 50 wt. %.
 11. (canceled)
 12. The method of claim 5, wherein theglass cullet is in a concentration range from 10 wt. % to 50 wt. %. 13.The method of claim 6, wherein the flux is in a concentration range from1 wt. % to 30 wt. %.
 14. (canceled)
 15. The method of claim 1, whereinthe batch comprises at least one of at least one of a metal oxide, ametal silicate, and a metal. 16.-22. (canceled)
 23. The method of claim1, wherein the batch comprises at least one of limestone and calciumoxide. 24.-29. (canceled)
 32. The method of claim 1, wherein the batchcomprises cullet, flux, and a decolorizer.
 33. The method of claim 32,wherein the cullet is in a concentration range from 25 wt. % to 50 wt.%.
 34. The method of claim 33, wherein the flux is a sodium flux and thesodium flux is in a concentration range from 2 wt. % to 15 wt. %
 35. Themethod of claim 34, wherein the decolorizer is manganese, manganesedioxide, selenium, or cerium oxide and is in a concentration range from0.25 wt. % to 5 wt. %.
 36. The method of claim 1, wherein the batchcomprises at least one of colorants, decolorants, fining agents,oxidizers, and reducers. 37.-134. (canceled)